This is the huge M777 howitzer that US Marines burned out while fighting ISIS in Syria

FORT BLISS, Texas – US Marines fired so many M777 howitzer rounds in support of Syrian Democratic Forces to oust the terrorist group ISIS from Raqqa that they burned out two barrels.

“They fired more rounds in five months in Raqqa, Syria, than any other Marine artillery battalion, or any Marine or Army battalion, since the Vietnam war,” Army Sgt. Maj. John Wayne Troxell, a senior enlisted adviser to the chairman of the Joint Chiefs of Staff, told Marine Corps Times at the end of January.

Here, you can see the size and scale of the barrel, which is almost 17 feet long.

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It’s fired by the lanyard, held below by Sgt. Greiten, who has completed multiple tours in Iraq and Afghanistan.

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Operators move the Triple 7 up and down – or to the side – with two wheels, one of which you can see in the lower left-hand corner.

“It’s awesome,” Spc. Garcia said about firing the Triple 7. “Limas don’t really get you wild up, but when you get to the hotels, it gets your blood going.” A lima (the code word in the NATO phonetic alphabet representing L) is a weaker charge, and a hotel (the code word for H) is stronger.

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Garcia, who deployed to Afghanistan last year, said his crew fired about 300 rounds “at known pools of enemy targets.”

Here’s a shot of the barrel from behind …

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… and here’s a look down the barrel from the front.

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The panoramic telescope is used to sight targets.

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And this is the fire control quadrant, which measures the elevation.

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Here’s what the Triple 7 looks like raised to the max …

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… and a shot of it lowered all the way down.

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Sgt. Shaw, who has served in Iraq and Afghanistan, says the only time it’s lowered like that is when the enemy is close — not a good position to be in, given that the cannon is meant for support.

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Shaw said his crew once took contact when he was in Afghanistan, but he understandably didn’t want to go into detail.

“If you’re receiving contact on this howitzer, that means all your front lines are not there anymore, or they have been able to flank the infantry,” he said.

All the Triple 7s at Fort Bliss bear the names of soldiers killed in combat.